The default is 15 seconds.• Change the hello-time parameter.PROTOCOL PVST modevlan hello-timeNOTE: With large configurations (especially those configurations with more ports), Dell Networkingrecommends increasing the hello-time.The range is from 1 to 10.The default is 2 seconds.• Change the max-age parameter.PROTOCOL PVST modevlan max-ageThe range is from 6 to 40.The default is 20 seconds.The values for global PVST+ parameters are given in the output of the show spanning-tree pvstcommand.Modifying Interface PVST+ ParametersYou can adjust two interface parameters (port cost and port priority) to increase or decrease the probabilitythat a port becomes a forwarding port.• Port cost — a value that is based on the interface type. The greater the port cost, the less likely the portis selected to be a forwarding port.• Port priority — influences the likelihood that a port is selected to be a forwarding port in case thatseveral ports have the same port cost.The following tables lists the default values for port cost by interface.Table 61. Default Values for Port CostPort Cost Default Value100-Mb/s Ethernet interfaces 2000001-Gigabit Ethernet interfaces 2000010-Gigabit Ethernet interfaces 2000Port Channel with 100 Mb/s Ethernet interfaces 180000Port Channel with 1-Gigabit Ethernet interfaces 18000Port Channel with 10-Gigabit Ethernet interfaces 1800Per-VLAN Spanning Tree Plus (PVST+) 787
